ARTEMIVSK, Ukraine - Combatants in the eastern Ukraine war ignored an impending cease-fire and escalated fighting Friday, as Russian-backed rebels sought to capture an important railway hub before the truce agreement takes effect.
Artillery shelling and gunfire reverberated in the area around the railway hub, Debaltseve, just south of this front-line town of Artemivsk, with reports that at least 18 people had been killed.
In a hospital courtyard here, ambulance crews hurriedly wheeled about bloodied, freshly wounded soldiers.
Medical helicopters buzzed in and out through the day. At a school, teachers herded children indoors when the booms of artillery started rattling windows.
The escalation erupted a day after the leaders of Russia, Ukraine, France and Germany negotiated a new cease-fire agreement, the second in the nearly year-old war. The new pact left many issues unresolved, and many diplomats consider it fragile.
Still, it is considered the best hope of resolving the conflict, which has left more than 5,000 people dead and raised tensions between Russia and the West to their highest since the Cold War era.
But rather than the hoped-for calm, the cease-fire appeared instead to cause a sharp escalation.
The agreement provided for a two-day lag between the signing Thursday in Minsk, the capital of Belarus, and the implementation here in eastern Ukraine at midnight Saturday. Ukraine's president, Petro Poroshenko, said it was a concession to the Russian-backed militants and President Vladimir Putin of Russia.
A frantic, bloody last-minute land grab ensued, with the Ukrainian-held town of Debaltseve a focus of this fighting. Debaltseve lies about halfway between Donetsk and Luhansk, the two redoubts of pro-Russian insurgents in eastern Ukraine.
After the overnight talks, Putin said Poroshenko refused to acknowledge that the separatist forces had surrounded up to 8,000 Ukrainian soldiers in Debaltseve, but the Russian leader said he hoped that consultations between military commanders would settle that matter.
The agreement requires that Ukraine and the rebels observe a cease-fire starting at midnight Saturday, then withdraw heavy weapons from the front line within two weeks. Later, Ukraine must restore pensions and public sector wage payments to separatists areas and amend its constitution to allow for greater local autonomy. If these provisions are fulfilled, Russia is to return control over a section of the eastern Ukrainian border by the end of this year.
"What we have on the table today gives us great hope," said Chancellor Angela Merkel of Germany, who helped lead the mediation effort in Minsk.
"There is a real chance to turn things around toward the better," she said, but added, "we have no illusions."
On Friday, a Ukrainian military spokesman, Andriy Lysenko, said 11 Ukrainian soldiers had been killed and 40 wounded in fighting after the cease-fire agreement and in the first day of the window before its implementation.
Lysenko said separatists had fired artillery at more than 30 towns and villages in the east.
In a sign the Ukrainian army, too, was trying to land blows before midnight Saturday, three children were reported wounded by artillery in the rebel-held town of Horlivka.
Some of the most intense fighting broke out along a tenuous, 31-mile Ukrainian supply route into the town of Debaltseve within hours of the signing.
Soldiers and medical crews interviewed here say rebels now control the road, and as evidence pointed to the ambulances and resupply trucks blown up by mines that now pepper a stretch of the route.
"I don't know what happened," Alla G. Neschadym, a nurse at the Artemivsk Central Regional Hospital, said in an interview of the battle that she said began in the late afternoon Thursday. "But I saw the results. The wounded came in all night long."